Abstract
The magnetic and transport properties are investigated in well-characterized Ge1-xMnx (x in at.%) amorphous semiconductor thin films for a large range of Mn compositions, prepared by using thermal co-evaporation onto oxidized Si or glass substrates held either at room temperature or quench condensed onto LN2-cooled surface. Magnetic hysteresis measurements at room temperature show saturation occurring by 1 - 2 kOe for all samples. The temperature dependence of the magnetization between 4 K and 300 K, measured at an applied field of 15 kOe and for zero-field cooled condition, exhibit a concave shape, different from the usual Brillouin behavior. The saturation magnetization at room temperature is found to range from 0.5 to 7 emu/cc. The highest magnetic moment observed per Mn ion is 0.76 Bohr magneton (μB) at 4 K at an intermediate composition x = 38.5 %. At x = 16.7 % where detailed transport measurements are carried out, the anomalous Hall effect is observed at 300 K, and the temperature dependence of the Hall effect is rather complicated. The magnetoresistance, being ∼1 % at an applied field of 50 kOe, changes sign at around 200 K.
Original language | English |
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Pages (from-to) | 2386-2396 |
Number of pages | 11 |
Journal | Journal of the Korean Physical Society |
Volume | 49 |
Issue number | 6 |
Publication status | Published - 2006 Dec |
Keywords
- Amorphous Ge-Mn thin films
- Diluted magnetic semiconductors
- High Curie temperature
- Magnetic properties
- Transport properties
ASJC Scopus subject areas
- Physics and Astronomy(all)